题目

设f（x）、g（x）都是单调函数，下列四个命题中正确的是( )①若f（x）单调递增，g（x）单调递增，则f（x）－g（x）单调递增;②若f（x）单调递增，g（x）单调递减，则f（x）－g（x）单调递增;③若f（x）单调递减，g（x）单调递增，则f（x）－g（x）单调递减;④若f（x）单调递减，g（x）单调递减，则f（x）－g（x）单调递减.A.①③B.①④C.②③D.②④Shanghai-More Shanghai people are renting cars to travel over the coming National Day holiday, Tom reported today.Most cars in large local car-rental companies such as Yongda, Anji and Dazhong are leased so far with the Buick Sport Utility Vehichle (SUV) in high demand.Santana and Jetta were previously the most popular car models rented by Shanghai people for travel, while the high-end Buick models have generated great interest among locals renting cars these years. However, the rent on a Buick GL or GS model is between 650 yuan and 750 yuan a day, nearly double those of the Santana and Jetta cars.Compared with Santana, Buick looks better, has greater capabilities and is safer and more comfortable, said a car leaser. “I don’t mind paying a higher cost for a Buick to enjoy the holiday,” he said.SUV cars are very popular in the car renting market, according to some car rental firms.“All the 31 Buick GL8SUV cars were leased out several days ago,” said an employee with the Shanghai Yongda Car Rental Co.local people are more inclined (倾向于) to go travel with groups of friends, so SUV cars are a better choice, said an industry analyst (分析家). Moreover, SUV car are safer on rugged and rough roads, the analyst said.According to the data, most people rented cars for seven days; a less number rented them for two or three days.1. What’s the best title for the passage ?How Shanghai People Spend Their Holidays Why So Many Shanghai People Rented Cars for HolidaysMore Shanghai Rent Cars for Holidays Shanghai Rent SUV Instead of Santana and Jetta 2. According to the passage we can see SUV is ________.the name of a car-rental company the name of an expensive car the name of an ordinary car the place for the holiday3. At present for how much money can you rent a Santana or Jetta for a day ?Between 650 yuan and 750 yuan. Between 350 yuan and 380 yuan. About 450 yuan. Less than 300 yuan. 4. Why do many people choose SUV cars for their holidays ?Because they are cheaper.Because they are convenient on rugged and rough roads.Only because they can run on bugged and tough roads.Because no Santana and Jetta can be rented now.